How should I select the features for predicting diseases (in particular when patients specify their health issues)?
So for Medical Prognosis, there are some variables that commonly come up like Age, Sex, Ascites, Hepato, Spider, Status of the disease and many others but it depends on the disease. You'll commonly encounter these variables if you're doing regression or classification.
Also, if you're reading Radiology Reports for getting the input for the model then you also have to take care of jargons. The same symptoms can be written in various ways but all point towards the same prognosis i.e., there can be synonyms for labels. Try reading this to get more information on how we can do information extraction from Radiology Reports. This is the famous CheXpert paper